A silver halide color photographic material (hereinafter referred to as a "color light-sensitive material") is essentially imagewise exposed to light, and then subjected to color development and desilvering.
In the color development process, silver halide grains which have been exposed to light are reduced by a color developing agent to silver, and the resulting oxidation product of the color developing agent reacts with a coupler to form a dye image.
In the subsequent desilvering step, developed silver produced at the development step is oxidized (bleached) with a bleaching agent having an oxidizing power to a silver salt which is then removed from the light-sensitive layer together with unused silver halide grains by a fixing agent which renders these silver salts and silver halide soluble (fixing). Bleaching and fixing may be effected separately as bleaching step and fixing step, or together as a blix step. These processing steps are further described in James, "The Theory of Photographic Process", 4th edition, 1977.
For the purpose of maintaining desired photographic and physical properties of the dye image or for maintaining processing stability, various auxiliary steps may be added to these essential processing steps. Examples of these auxiliary steps include a rinse (with water) step, a stabilizing step, a film hardening step, and a stop step.
These processing steps are normally effected by means of an automatic developing machine. In recent years, small-sized automatic developing machines called "mini-labo" have been installed in retail stores to provide rapid processing services to customers.
Under these circumstances, it has been keenly desired to speed up processing. It has also been desired to considerably speed up the bleaching step.
However, the ferric complex of ethylenediaminetetraacetic acid, which has been heretofore used in the art, is essentially disadvantageous in that its oxidizing power is weak. In spite of some improvements such as the use of bleach accelerators (e.g., addition of mercapto compounds as described in U.S. Pat. No. 1,138,842), the objective, i.e., rapid bleaching has not yet been attained.
Furthermore, when such a bleach accelerator is used, the bleaching power is considerably reduced due to the deterioration of the bleach accelerator, making it impossible to reduce the replenishment rate. As a result, the objective of considerably reducing the amount of waste liquid cannot be attained.
As bleaching agents which can attain rapid bleach there have been known red prussiate, iron chloride, bromate, etc. However, red prussiate cannot be widely used due to problem of environmental protection. Iron chloride cannot be widely used due to the inconvenience of difficult handling due to metallic corrosion. Bromates cannot be widely used due to the solution instability.
It has therefore been desired to provide a bleaching agent which provides for a rapid bleaching that can be effected with ease of handling and without any problem of discharge of waste liquid.
In recent years, ferric complexes of 1,3-diaminopropanetetraacetic acid have been disclosed as bleaching agents which can meet these requirements.
However, these bleaching agents have some disadvantages. One of these disadvantages is that these bleaching agents cause bleach fogging accompanied by bleach. As a process for eliminating bleach fogging there has been proposed a process which comprises the addition of a buffer to the bleaching solution (disclosed, for example, in JP-A-1-213657). (The term "JP-A" as used herein means an "unexamined published Japanese patent application".) However, this improvement leaves much to be desired. In particular, in the case of rapid processing where color development is effected in 3 minutes, heavier bleach fogging can be caused due to the use of a highly active developer.
Further, the use of a processing solution having a bleaching capacity comprising a ferric complex of 1,3-diaminopropanetetraacetic acid causes an increase in stain during storage of the photographic material after processing.
Another problem is that the use of a bleaching solution comprising a ferric complex of 1,3-diaminopropanetetraacetic acid causes an intensification of magenta dye on the dye image portion which leads to a change in gradation during storage after processing.
A further problem is that when a shorter bleaching time is used, even though a bleaching solution comprising a ferric complex of 1,3-diaminopropanetetraacetic acid is used, since cyan dye on the image portion tends to become a leuco dye, the recovery to the original color is inhibited.
It is also a problem that when a processing solution having bleaching capacity comprising a ferric complex of 1,3-diaminopropanetetraacetic acid is used, especially at bleach-fixing step where bleaching and fixing are carried out simultaneously, the stability of the solution is extermely poor. When such a solution is subjected to a continuous processing, desilvering capacity extremely decreases as compared with the starting of the processing, or precipitation forms.
It has therefore been desired to provide a novel processing composition having a bleaching capacity which can substitute for these bleaching agents and a processing method using such a processing composition.